The latest phone-hacking allegations are without doubt THE media story of the week, and possibly the tipping point which will make it one of the media stories of the decade, which ushers in a genuine inquiry into the practices of newspapers, and forces change amid the extensive criminality.

As I said here last night, the disgust and revulsion felt by decent people at the idea of a murder victim’s phone being hacked, and messages deleted which gave her family some hope she might still be alive, takes this whole murky saga to a new, hideous and, frankly, quite evil depth.

I was with Boris Johnson this morning to launch a London to Lisbon bike ride being done by four teenagers for Leukaemia and Lymphoma Research. There were some hard-bitten and experienced Fleet St photographers there to record the event. These men know a thing or two about what newspapers get up to in pursuit of a story. They were revolted at the latest revelations, and so is every other person I have heard speak about it.

The police having made such a hash of the first investigation into phone-hacking, News International having handled the issue so badly and so dishonestly, and politicians having been reluctant to get too involved, the strategy of all three seems to have been ‘let’s just will it away’. But as I have been saying for a long time, this was a story that was going to keep going until all three got to the very bottom of it. We thought the bottom of the barrel had already been reached. But no, every revelation takes us a little bit further towards somewhere marked absolute amorality.

Back when I was a journalist, I can remember then Culture Secretary David Mellor warning the press they were ‘drinking in the last chance saloon.’ The Press Complaints Commission was born, a body of the press, by the press, for the press, and one of the reasons self-regulation has failed, and the press have been drinking away merrily in many saloons since.

But the Milly Dowler revelations, and the now entirely believable suggestions of similar activity concerning the Soham murder victims, mean there is no way David Cameron can avoid ordering some kind of broader inquiry into the culture and practices of newspapers once the police investigations are complete. If he does avoid doing so, it will be an enormous failure of leadership and moral courage.